Cyanid process.



No. 840,040. PATENTED JAN. 8, 1907. H. B. GOBTSGHIUS.

GYANID PROCESS. APPLICATION FILED 001.028.1000.

WMWWWM UNITED 'STATES PATENTv oEEIoE. HOWARD B. GoErscHn-Js,r oF Diiiionr. NEw JERsEY.

CYANID inoolss l To all whom it may concern,-

Be it known that I, H owAnn B. GoETson1Us, a citizenof the United States, and a 4 resident ofDumont, in the county of Bergen' and State of New Jersey,have invented cerf tain new and Yuseful Improvements in Cyanid Extraction Processes, ofwhich the fol,

lowing is a specification.

yinvention relates to 'the so-called .cyanid extraction process for gold and silver; and it has for its object the more complete extraction of said metals by the cyanid solution, aswell as greaterra idity of extraction land the ability te hand e coarser grades of ore. p v i For this prpose my invention consists, essentially, 1n thoroughly oxygenating the cyanid `solution while under pressure and prior to the -treatmentof the ore therewith, then forcing this', solution through the ore against a back ressure, then releasing said fessure, whereg due to the simultaneous isengagemento gas because of the release of pressure, the ore is agitated throughout,

.and finally increasing the pressure slightly above the initial degree in order to redissolve the remaining disengaged gas, to ether with f any films or bubbles adhering to t e particles of ore. Y l

In the present practice of cyaniding ores containing p cius metals two methods are most commo y 'employed-viz., simple percolation of the iiuid through the ore or me- .clllanicall agitation with the cyanid solution.

In both of these methods it has beenl found necessary "to supply oxygen tothe cyanid solution or to the ore andV solution in order to 4insure an ecient extraction ofthe contained metals. When simple percolation 'is resorted to, the solution isaerated or oxygenated as `thoroughly, as possible and then permitted-to percolate throu h the ore in the various cycles anywhere om i iiteen to thirty da s.

treatment. the oxygenated solution is final y conveyed throughout the mass toall the particles of the ore. and a ood-extraction is obtained in the ca'se oft e gold `but many compounds of silver are ectly acted upon by the dissolving .r iuids. 'If `the ore to be percolated is crushed fine by .the dry process, thev cost of thel operation 1s Y elating,

much increased andalso the diioultyofpen,

and there is considerable loss inthe linefdust' carried away.l "If Wetcrushed, some of thesediiculties are removed; but

.other mechanical cliccaresubst itu'tcd.v In

Y' Specification of Letters Patent. Application and nach ze, 190s. serial No. 308,579.

provided.

. Patented Jan. 8, 1907.

mass than by ordinary ercolation it will befound that thegrains o ore become covered with bubbles, thus protecting the ore from intimate contact with the cyanids. The a paratusreq ed vis valso much more compicatedand expensive. y.

The nature of my invention will be best understood in connection with the accompanying drawing, which illustrates diagrammatically the general arrangement of the apparatus employed. y

10 represents an air-compressor taking air through an inlet-pipe 11, provided 'with a valve 12. I l

13 is a reservoir for the air, from which air is` delivered into the solution-tank 14. A safety-valve 15 is provided in connection with saidreservoir for the air, also a' relief or blow-oil` pipe.16. Y Connections are also provided. whereby the .said reservoir may be placed in communication with the ore-tank 17. A relief-valve 18 is provided between the two tanks 14 and 17. Pressure-gages 19 are placed vat the desired points to perm'it the observation of th'e'pressure existing in the two said tanks'. Provision is made Wherebythe solution-tank 14 may be placed in communicationwith the ore-tank 17 both at the top and bottom. .The ore-tank 17 contains a false -nicationwith the solution-tank 14 when desired. A drain 23 for theore-tank 17 is also In c out myy invention Irst sufficiently aerate the cyanid. solution in the closed .solution-tankM-,with air or oxy en under pressure by forcing it into sai solution throughV a perforated pipe 24 lo`r any ofthe usualapparatus for -finely dividing the stream of gas and set in such va manner as to stir the liquid while the gas fis pass' into it. The tank or chamber 14 in wliicv this aeration This box or.

IOO

takes place is connected with a relief-valve 18, throu hWhich the unabsorbed excess of gases is aIloWed to pass off, and lthe safetyvalve y is set at a pressure proportionate to the degree of oxygenation required 'for the subsequent treatment of the ore and, other things being equal, sufliciently high tokelep in liquid'form any cyanogen Which may be the entire mass of ore.

liberated. 4The cyanid solution is--thus saturated With the required gas and is still, no gas being evolved so long as the initial pressure upon the liquid is maintained. In an` other closed tank 17'or, if desired, in another compartment 4ofthe tank in which the oyanid solution is aerated is placed the ore on a false bottom 20, covered With duck orsoine other suitable fabric. The ore-may be dry crushed `and as coarse as'tWenty-fourl mesh, including the siftings of finer mesh. Into this mass of ore I force the aerated cyanid solution, va suitable back pressure being maintained at the proper point in said ore-tank by means of the safety-valve 15. The cyanid solution therefor passes entirely through the ore Without -disturbing or channelin it. It is allowed to flovv' vthrough the ore in t is fashlion for some time, discharging to the zinc'- boxes 22, the pressure in the tank being -kept up to the initial degree While this-part of the operation'is going on. After a time `the flow. o cyanid solution bothto and from said oretank is stopped. The pressure in `the oretank is thxen partly released through the relief-valve 18', causing a simultaneous-'disengagement of the contained gasesthroughout By this means the Whole mass of ore is thoroughly agitated and oxygenated, each particle beingdisturbed in its relation to its neighbor and the gases-entra p'ed in the-interstices lof the ore released Wit `a tendency toffracture the particles containing them. Bythusreleasing the pressure upon said massof ore a very convenient and thorough agitation oftheore is: obtained, `al- `lowings of the agitation of'a massof material much larger than could behandled by mechanical means and with aiminimum expenditure of labor and power.' 'The release of pressurehavingtaken place,theforcing of cyanid solution from theaerati11g-tauleA throu h goliandsilver, Where airI isblown .through such. a mass of' ore, asis sometifmespraef'ced, this isnot accomplished, forthe particles become surrounded' by an adherent film orfbubble of gas which prevents the solution from coming into perfect contact with them.

Because of the simultaneous and complete` gaseous agitation and because of the complete penetration of the ore and its particles 7o by solution carrying a sufficiently large quantity of oxygen Iam able to deal with a coarser product containing a large or small quantity of fine material entirely by percolation and Without reha'ndling the Whole or 75 part in other apparatus, such as slime-separators, agitation-tanks, iilter-presses, &c. The tendency to separate the coarse from the fine portions of the ore is also reduced to a v minimum, so that the Washing out ofthe im- 8o perfectly-extracted fine material (which takes place when the airisblown through) is prevented. I

In handling large quantities of'ore I may arrange a number of ore-tanks in series and for redissolvin the gases, or I- may Work' a 9o number ofta s independently from a central tank containing the said cyanid solutio under pressure. l

After the solution lof 'cyanids .containing a Acertain proportion ofthe precious metalshas 9 5 ,assed from the'tank` 17 containin the ore itis run into the `2.incbox or tube-m1ll22'and p'assedfover the zinc or other materials used to separatey the goldand silverfrom said solution'and when deprived of them is drawn xqo back into the tan or' compartment 14 for 'aerationJof-the solutions, reaerated, and then again passed through the ore. This is repeated 'as many times as-may be necessary to completentheextraction, thesolution being :o5

strengthened With neWcyanid' when a test shows this to be'necessary. The precious metalsL hav-ing been extracted, acertain ,amount' of liquid remains, and air'under pressureis now supplied above the' ore, by 1ro which means a quantity of the liquid is forced` out, and' this iis followed by awashingwith Waterfol-cedthrough 'either' from `to or'botl tom until the esca in'lliquid isfoun to be as vfree'of anything o value as may be required. 1 1

The last-1 of the water is' finally forcedfout. of

the ore-in thesamer-manner 'asthe eyanid' solut-ion already referred to, and this `Wash- Water is brough't'up to the propenstren' -th Withl new cyanid and used to re lace sou- 12o .tionssthat-have become worthless: yuseand to standardize` those which have become weak.

, In--this-way lthe exhaustedvoreisdelivered ina muehvdriler condition'vthanfb p'ercolat- 'iz5 ing BOPGnta-nks; and becauseoi't `'s and the minimum amount \of 'fluidfrequired in a-fcycle otheoperation and'also because the' operation- -is carried on iny tanks and.- evaporation'therebyfprevnted a= great saving'rof 13o` Water is made, whichA is a matterofimpor# tance in hot and dry climates. "Theprocess'- is Worked to the best advantage .at the -pressure required to maintain cyanogen gas a liquid, and where necessary the' ore is ke t, alkaline by the usualimeans to correct t e acidity ofthe ore and to absorb any released cyanogen or hydrocyanic' acidthat may have been produced. 'I have found that usually a pressure of from sixty to ninety pounds per square vinch 'ives Vsatisfactory results for oxygenating t e cyanid solutior'ipfo'r percolation, &c. f

Where the ores contain .refractory combi-v nations of the recious metals, and especially in the case ofs` ver, theA ore is given a prelimii nary treatment with a watery. solution of chlorin, bromin, or hypochlorites aerated with oxygen or air in the same manner as hereinbefore described and in which the'pro-4 duction and release of pressure is allowed to take place as already described in order to Wholly or in part break up the said refractory combinations, agitate the body of ore, dissolve the adhering gases, and prcpareth'e material for the more ready action of the solution of the cyanids.

What I 'claim as new, and desire to secure by Letters Patent of the United States, is- 1.`.lhe herein-described cyanid extraction process, consisting. in: first aerating the cyanid solutionunder pressure greater than atmospheric pressure; then forcing the aerated solution .under said pressure through the ore to be treated and against a suitable 'back pressure.

2. The herein-described cyanid extraction process,l consistin in: iirstaerating the cyanid solution under pressure.; then' forcing said aerated solutionl under the initial pres-l sure through the ore to be treated and against a suitable vback pressure; and then releasing the pressure lupon the mixture. Y l

3. lThe he 4cui-described cyanid extraction process, con istin -inznrst aerating the cyanid solution un er pressure; thenforcing said aerated solution under the `initial pressure throu h the ore to, be treated fand against sure upon the mixture; and finally increasing the pressure rupon said mixture slightly above the initial'pressure.' y 4. The hereindescrzibed cyanid extraction process, consistingfin: treating the ore with an aerated cyanid solution under pressure,

- pressure to mechanically. stir the mass of ore andwredissolve the remaining released gases. 5. The herein-described cyanid extraction process, consisting in treating the ore in a closed vessel with an aerated cyanid solution under pressure then releasing the pressure to mechanically stir the mass of ore; and finally increasing the pressure slightly above the initial pressure to dissolve the remaining disen;M gaged gas and any gas films or bubbles adhermg to the particles of ore. v

.A 6. The lherein-described ycyanid extraction Y alternately releasing l ,nd increasing said pressure upon the mixture. t

Sign York andState-ef-N ew March, A. D. 1906. y

HOWARD B. GOETSCHIUS. Witnessesz FREDK. Scm'm'rz,

'a suitablel ackpressure ;.re leas'ing'the' presn Samir Y lO. Yunrzxr.`

process, consistingv in a ypreliminary treat-- ment of the ore 'witha watery. solution of` chlorin or the like aerated With oxygen'or air under pressure' las set forth; and then treating the ore with `cyanid-solutionl under-p ressure,

ed atN ew York, in the county of NewA fYork, this 26th-day of .and alternately releasing and increasing the process, consistinginz-a preliminarytreatprocess,consisting in; a"preliminary treat- A 

